1. Field of the Invention
The invention relates generally to nucleic acid detection devices, and more particularly a detection device, that incorporates bionanosensor technology to detect duplex DNA. The device is particularly applicable in detecting the presence or absence of duplex DNA and its correlation to the diagnosis of infectious diseases including tick-borne infections and coinfections such as Lyme disease, babesiosis, anaplasmosis, bartonellosis, and the like, foodborne disease such as salmonellosis, and diseases relating to viral infections such as flu or H1N1.
2. Description of the Related Art
A biosensor is a device for the detection of the presence of an analyte, such as DNA, proteins, peptides, or small molecules, using known interactions between a targeted analyte and a binding agent, typically a macromolecule. Biosensors have been used, for example, in blood glucose monitoring for diabetics, remote sensing of airborne bacteria, identification of health related targets, genetic screening and the like. Biosensors also have utility in disease prevention, diagnosis, and management.
An infectious disease is any disease caused by a pathogen which subsequently grows and multiplies in the body. Infectious diseases have been a serious issue for humans for hundreds of years, and can result in enormous human suffering. For example, Lyme disease, or borreliosis, is an emerging infectious disease caused by at least three species of bacteria belonging to the genus Borrelia. Borrelia burgdorferi is the predominant cause of Lyme disease in the United States, whereas Borrelia afzelii and Borrelia garinii are implicated in most European cases. Early manifestations of infection of Lyme disease may include fever, headache, fatigue, depression, and a characteristic skin rash called erythema migrans. Left untreated, late manifestations involving the joints, heart, and nervous system can occur. In a majority of cases, symptoms can be eliminated with antibiotics, especially if diagnosis and treatment occur early in the course of illness. Late, delayed, or inadequate treatment can lead to late manifestations of Lyme disease which can be disabling and difficult to treat. Salmonella enterica is a bacterium which causes salmonellosis, a common foodborne infection/intoxication in humans. Rapid and sensitive detection methods of Salmonella in a food supply would inhibit and even prevent major outbreaks of salmonellosis. Furthermore, early detection of Salmonella pathogenic DNA in a patient's blood would lead to prompt early treatment. These are but two examples of how early treatment of infectious diseases is often critical to effective treatment. It is therefore paramount that infectious diseases be identified early and quickly.
Identification of specific infectious diseases is currently performed in a variety of ways known in the art, including chemical and physical assays, and microscopic examinations. Although various methods and devices are available for detecting an infectious disease, it is appreciated that there is still a need for a reliable, sensitive, simple, convenient, versatile, and cost-effective method to detect the presence of a disease-causing pathogen in body fluids, food samples, water samples, air samples at the earliest stage possible to prevent the spread of the disease and prevent more serious health harms. There is also a need for a detection device that can be used in clinical or field setting and requires only minimal training to use.
Since their discovery, nanotubes have found extensive use in the fields such as electronics, optics, and other fields of materials science. It has been suggested that nanotubes can be used to detect biomolecules of interest, such as proteins and nucleic acids. For example, U.S. Pat. No. 6,376,177 discloses a gene probe biosensor employing field surface enhanced Raman scattering for direct spectroscopic detection of hybridized molecules without the need for labels.
U.S. Pat. No. 7,052,854 discloses a nanostructure-based assembly that is applied to bodily fluid samples for the ex vivo detection of analytes/biomarkers of interest.
U.S. Pat. No. 6,958,216 discloses a biological sensing device including a pair of carbon nanotube tubules at a fixed distance apart, and a biological molecule attached to the carbon nanotube tubules through a metallic material. The biological molecules provide electrical connectivity between the pair of nanotubes tubules.
U.S. Pat. No. 6,824,974 discloses a biosensor includes a first electrode, a second electrode and a binding agent such as a biological macromolecule connecting the first electrode and the second electrode.
Zelada-Guillen et al. (Angew. Chem. Int. Ed. (2009) 48:7334-7337) disclose a method and device for detecting living bacteria using a carbon nanotube-based potentiometri aptasensor. In this invention, Salmonella bacteria are attached directly to functionalized SWCNT which causes the pH of the medium to change. The change in pH is correlated with the concentration of bacteria in the medium.
What is needed in the art is a convenient, cost effective, and rapid biosensor detection device that is effective to detect the presence of DNA of interest, and in particular DNA of an infectious organism. The present invention is believed to be an answer to these needs.